Compressed air dryer-handle attachment filter

ABSTRACT

A replaceable moisture filter handle attachment is provided for removing moisture from compressed air driven tools such as paintspray guns. The filter, which readily opens for replacement of cotton batting filter material, attaches in the compressed air line input to the handle of the tool employed.

United States Patent [191 Maggiacomo et al.

[ Nov. 18, 1975 COMPRESSED AIR DRYER-HANDLE ATTACHMENT FILTER [75]Inventors: William D. Maggiacomo, Beverly;

Fred A. Winslow, Marblehead, both of Mass.

[73] Assignee: William D. Maggiacomo, Beverly,

Mass.

[22] Filed: Oct. 9, 1973 21 App]. No.: 404,229

[52] US. Cl. 239/526; 55/417; 55/418;

55/502; 55/512; 137/550 [51] Int. Cl. B05B 7/02 [58] Field of Search55/417, 418, 480, 481,

1,750,632 3/1930 Farmer 55/480 2,251,964 8/1941 Stackhouse 2,558,1256/1951 Cullen 2,598,818 6/1952 Mairhead....

3,021,871 2/1962 Rodgers 3,557,536 1/1971 Ririe 3,681,899 8/1972 Grote3,748.837 7/1973 Billeter 210/452 Primary E.\'aminer.Bernard NozickAttorney, Agent, or Firm-Thomas C. Stover, Jr.

[57] ABSTRACT A replaceable moisture filter handle attachment isprovided for removing moisture from compressed air driven tools such aspaint-spray guns. The filter, which readily opens for replacement ofcotton batting filter material, attaches in the compressed air lineinput to the handle of the tool employed.

8 Claims, 3 Drawing Figures US. Patent Nov. 18, 1975 Sh6t 1 0123,920,189

FIG. I

US. Patent Nov. 18, 1975 Sheet 2 of2 3,920,189

COMPRESSED AIR DRYER-HANDLE ATTACHMENT FILTER FIELD OF THE INVENTIONThis invention relates to a means for demoisturizing compressed air,particularly an apparatus for demoisturizing compressed air for use inpower tools.

THE PRIOR ART Compressed air is widely used as a means for poweringtools, such as hand tools including spray paint guns, drills, buffingtools and the like. The problem in the use of such tools is ridding thecompressed air of moisture which accumulates when humid air iscompressed, e.g. in a compressor. The moisture in the compressed air caninterfere with the proper functioning of the power tools where themoisture becomes a nuisance. A particularly adverse effect of moisturein the compressed air appears, for example, in the use of spray painttools, as, for example, in the spray painting of vehicle bodies. If notremoved, the moisture in the compressed air passes into the spray gun tomix with the spray paint as it emerges from the gun nozzle, formingpaint blisters on the vehicle body surface which, of course, is a highlyundesirable result.

Efforts have been made to remove such moisture from the compressed air.Typically, a filter box is installed in the compressed air line andmounted on the wall and the filter removes most of the moisture from theair passing through, at least initially. However, in a short time thewall filter becomes saturated and no longer effectively removes moisturefrom the compressed air passing therethrough. These relatively largefilters are expensive and difficult to replace, and as a result are notreplaced as often as they should be, so that effective moisturefiltration does not, in practice, take place except infrequently.

It has been proposed to put cotton batting in the handle of the spraygun, the batting being pushed well up into the handle with a stringhanging down to assist removal thereof when the batting becomessaturated and no longer effective. The batting is, of course, in thepath of the compressed air and initially this batting serves to removemoisture from the compressed air passing through the spray gun. However,the batting has proved difficult to remove in that the compressed airblows the pull string up against the batting which becomes moist, andstring and batting adhere to each other, or the string can break off, ineither case making removal of the batting difficult. And in the mannerof the wall filter above, the batting is not replaced as often asnecessary due to the difficulties thereof. However, the batting cannotbe employed with other tools in that it is inserted in the handle of thespray gun and thus is not interchangeable with other compressed airpower tools. See US. Pat. Nos. 1,822,622 to Hermann and 2,959,358 toVork.

There is therefore, a need and market for an easily accessible filtermeans for removing moisture from compressed air, which filter meansprovides for easy and inexpensive replacement of filter material andwhich unit is interchangeable for use with various power tools.

SUMMARY There has now been discovered a compressed air demoisturizerwhich permits ready replacement of filter 2 material therein, which isinterchangeable with various power tools, is low-cost and which in oneor more embodiments readily attaches to the handle of the power toolbeing used.

Broadly, the present invention provides a replaceable moisture removerfor compressed air driven tools comprising a tubular retainer whichattaches to said tool proximate the compressed air inlet thereof suchthat the compressed air passes therethrough, a moisture collectingchamber within the retainer, the retainer having a screen positioned atthe exit end of the chamber, means to open the chamber to remove theused moisture filter therefrom and to insert a new moisture filtertherein and means to close the chamber before reactivating the powertool.

DESCRIPTION The present invention will become more apparent from thefollowing detailed specification and drawings in which:

FIG. 1 is an elevation view of an apparatus employing an embodiment ofthe present invention;

FIG. 2 is an enlarged sectional elevation of the moisture removerembodying the present invention; and

FIG. 3 is a plan view of the moisture remover of FIG. 2

Referring now to the drawings, cotton batting 11 is employed in moisturefilter 10 which filters moisture from compressed air passingtherethrough in line 13 from compressed air reservoir 14 and compressedair source 16 as shown in FIGS. 1 and 2. The demoisturized air thenpasses through the handle 18 of spray gun 20 and mixes with paint 22which is fed from container 24 by feeder tube 26 and the compressedair-paint mixture is discharged from spray gun 20 at spray nozzle 28 asshown in FIG. 1. The spray gun 20 is activated by depressing triggervalve 30.

The moisture filter has an upper tubular half 32 and a lower tubularhalf 34 which form a filter chamber 36 as shown in FIG. 2. The upperfilter section 32 has threads 33 therein and the lower tubular section34 has threads 35 thereon which enables the respective tubular sections32 and 34 to be readily screwed together or apart for prompt access tothe filter chamber 36 as shown in FIG. 2. Rubber washer 39 resilientlyseparates tubular sections 32 and 34 as shown in FIG. 2. Within thefilter chamber 36 are positioned first filter screen 38 at one end ofsaid chamber and, at the other end of said chamber, second filteringscreen 40. Positioned between said screen is replaceable filtermaterial, e.g. cotton batting for moisture collection as shown in FIG.2.

Compressed air line 13 attaches to the moisture filter l0 threaded exitport 42 while spray gun 20 attaches to the moisture filter 10 atthreaded exit port 44, also as shown in FIG. 2. The rate of compressedair flow through the inlet port 42, moisture collection chamber 36 andexit port 44 of moisture filter 10 can be controlled by rotatablepressure control valve 46, having orifice 47, which communicates withmoisture chamber conduit 49 as shown in FIG. 2.

The moisture filter 20 described above can, if desired, be reversed withthreaded port 42 being hooked to the spray gun 20 and threaded port 44being connected with the compressed air line 13.

In operation, compressed air is fed from the compressor via line 13 tocompressed air reservoir 14 and thence by a line 13 to moisture filter10, where the air passes through inlet port 42 through pressure controlvalve orifice 47, through moisture removal chamber conduit 49, throughthe first filtering screen which removes dust particles and the like,then through the cotton batting moisture filter within the moistureremoval chamber, thence through the orifice of the rubber,

washer 39, through the second filtering screen 40 for removal of cottonfibers and other impurities, then through exit port 44 where thedemoisturized compressed air enters the spray gun through the handle 18.The dernoisturized compressed air then mixes with r the paint and spraynozzle 28 of the spray gun 20 as stated above.

The moisture filter of the present invention provides a unit whichreadily screws apart for quick replacement of the filter materialtherein, after which the unit is readily put together; The moisturefilter employed to the present invention thus readily provides for thereplacement on the filter material at the end ofthe day,

for shorter period of use or in dry weather at the end of several days,i.e. whenever the filter material loses effectiveness. Because of theease of replacement of such filter material, the workmen will be moreinclined to promptly make such replacement and the air power tools,including the spray gun, are rendered more effective. Moreover, themoisture remover embodying the present invention can be employed withvarious compressed air power tools for greater use and effectivenessthereof.

It is important that the moisture remover embodying the presentinvention be readily openable to the moisture removing chamber whetherby aportal in the side of the one piece moisture filter or a two or morepiece moisture filter which has components which come apartreadily andas readily can be reassembled. The multi-piece filters can be attachedby screwthreads, clamps, snap means, screws, latches and the like.Preferably, however, the multi-piece moisture filter is attached bymeans of mating screw threads, an example of which is shown in FIG. 2..

The moisture filter can be made of various materials, e.g. wood,plastic, metal and the like, preference being given to metal such asaluminum and brass and/or durable plastic such as polystyene.

The moisture filter can be tubular or angular in crosssection, providedit defines a compressed air conduit therethrough. Preferably, themoisture filter defines a rounded or tubular conduit for compressed airthere- I through. Moreover, a moisture filter embodying the presentinvention, can have a pressure control valve built-in as shown in FIGS.2 and 3 of the drawing. How- 4 where desired, including the entrance andexit ends thereof.

The filtermaterial can be various moisture absorbing materials, e.g.cotton, wool,cell-ulose material including porous paper, urethane andporous metal filters,

e.g..steel, aluminum and the like. Preferably, because of its low cost,availability and high moisture absorption characteristics, cottonbatting is preferred.

The moisture filter of the present invention can, as

indicated above, be installed on the handle of the compressed air tool.However, the moisturefilter can also be installed in the air line at anypoint desired. Preferably for convenience, the moisture filter oftheinvention is installed at the inlet of the compressed air inlet ofthe power tool being employed.

What isclairned is:

l. A replaceable moisture filter for a compressed air driven toolcomprising, a tubular retainer which attaches to said tool proximate thecompressed air inlet thereof such that the compressed air passes there,

through, said retainer having at least two members which fit togetherincluding a first member secured within a second member to define afilter chamber: therein, a moisture collecting filter sized to fitwithin said chamber. (within said retainer), an inlet channel passingthrough said retainer to an inlet endof said chamber, an outlet channelpassing through said retainer to an exit end of said chamber, (a) anexit screen releaseably secured between shoulders defined by said ifirst and second members at the exit end of said chamher, an inletscreen'positioned at the inlet end of said. chamber on a shoulder onsaid first member, means to separate said first and second members toopen said chamber to insert and replace a moisture filter therein 3. Themoisture filter of claim 1 attached tothe han dle of a paint spray gun.

- 4. The moisture filter of claim 1 whereinthe tubular r retainer is atwo part tube which comes apart to reveal said chamber for replacementof said moisture filter therein. 7 v

5. The moisture filterof claim 4 wherein said retainer comprises twothreaded components which screw together.

1 6. The moisture filter of claim 5 wherein the, retainer 1 componentsare each hexagonal shaped in cross-sec, 7

tion.

7. The moisture filter of claim 1 wherein said tubular retainer is atwo-part tube, the lowertube fitting inside the upper tube to define anannular shoulderat the upper portion of said chamber, said screenextending 7 across said lower tube and being supported in place on saidshoulder.

8. The moisture filter of claim 7 wherein said'filter is positioned on aresilient annular washer positioned on said shoulder.

1. A replaceable moisture filter for a compressed air driven toolcomprising, a tubular retainer which attaches to said tool proximate thecompressed air inlet thereof such that the compressed air passestherethrough, said retainer having at least two members which fittogether including a first member secured within a second member todefine a filter chamber therein, a moisture collecting filter sized tofit within said chamber (within said retainer), an inlet channel passingthrough said retainer to an inlet end of said chamber, an outlet channelpassing through said retainer to an exit end of said chamber, (a) anexit screen releaseably secured between shoulders defined by said firstand second members at the exit end of said chamber, an inlet screenpositioned at the inlet end of said chamber on a shoulder on said firstmember, means to separate said first and second members to open saidchamber to insert and replace a moisture filter therein and means torejoin said members to close said chamber said moisture collectingfilter being positioned between said screens.
 2. The moisture filter ofclaim 1 having a pressure control valve inserted therein to govern theflow of compressed air therethrough.
 3. The moisture filter of claim 1attached to the handle of a paint spray gun.
 4. The moisture filter ofclaim 1 wherein the tubular retainer is a two part tube which comesapart to reveal said chamber for replacement of said moisture filtertherein.
 5. The moisture filter of claim 4 wherein said retainercomprises two threaded components which screw together.
 6. The moisturefilter of claim 5 wherein the retainer components are each hexagonalshaped in cross-section.
 7. The moisture filter of claim 1 wherein saidtubular retainer is a two-part tube, the lower tube fitting inside theupper tube to define an annular shoulder at the upper portion of saidchamber, said screen extending across said lower tube and beingsupported in place on said shoulder.
 8. The moisture filter of claim 7wherein said filter is positioned on a resilient annular washerpositioned on said shoulder.